/*
 * Alloy Analyzer
 * Copyright (c) 2002 Massachusetts Institute of Technology
 *
 * The Alloy Analyzer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * The Alloy Analyzer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with the Alloy Analyzer; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package alloy.util;

import java.util.Iterator;

/**
 * A "regenerating" iterator that takes an interface for creating
 * a fresh {@link Iterator}, and implements a {@link ResettableIterator}
 * that creates a fresh {@link Iterator} when it needs to {@link #rewind}.
 */
public class RegenIterator implements ResettableIterator {
    public static interface IterMaker {
	public Iterator makeIter();
    }

    private IterMaker _iterMaker;
    private Iterator _iterator;

    public RegenIterator(IterMaker iterMaker_) {
	_iterMaker = iterMaker_;
	_iterator = _iterMaker.makeIter();
    }

    public boolean hasNext() { return _iterator.hasNext(); }
    public Object next() { return _iterator.next(); }
    public void rewind() { _iterator = _iterMaker.makeIter(); }
    
    public void remove() throws UnsupportedOperationException
    { throw new UnsupportedOperationException("RegenIterator.remove()"); }
}
